Among those interests is a strategic one, McConnell and other Republicans said. By joining with Democrats in an area of mutual accord, they are seeking to demonstrate that the Senate can function in a polarized political environment. That, they believe, can deflate a Democratic push to undo the filibuster — the 60-vote supermajority rule than can allow a minority to block most legislation — while setting up a stark contrast as Democrats move alone on a $3.5 trillion economic package…

He summarized his political analysis of Tuesday’s vote by noting high levels of support for infrastructure investment among GOP voters and the fact that both Obama and Trump had sought to tackle the issue. “My judgment was, it would not hurt the Republican Party to be part of an agreement to do something the American people desperately need,” he said.

His support came after Democrats agreed to set aside their attempts to undo the 2017 Republican tax overhaul, saving any tax hikes for their broader economic legislation. That, in his view, comported with the clarification he gave earlier this year after his “100 percent” comment prompted Democratic outrage: “I want to do business with the president, but he needs to be a moderate.”